The present invention relates to repair of flaws or voids in bodies, and in particular to repair of surface accessible flaws or voids in bodies such as cracks, breaks or pits in glazing panels or the like.
Flaws or voids such as cracks in bodies such as glazing panels occur in a variety of configurations. For example damaged vehicle windscreens may exhibit elongate running cracks, or breaks classified in the art as, for example, xe2x80x98bulls-eyexe2x80x99 xe2x80x98starbreakxe2x80x99, xe2x80x98clover leafxe2x80x99, xe2x80x98bee""s wingxe2x80x99, xe2x80x98half moonxe2x80x99 or xe2x80x98combinationxe2x80x99. Frequently such damage flaws are repaired by means of introducing a repair material into the flaw or void, and subsequently hardening the repair material. For example, for repairing crack damaged glazing panels (such as vehicle windscreens) a flowable resin is introduced into the crack and subsequently permitted to harden. Repair resin may be applied under vacuum (to enhance de-gassing of the resin), and mechanical means (such as a plunger) may be utilised to force the resin into the crack. An arrangement has been proposed in which high frequency vibrations are imparted to the body to promote resin infilling breaks. Such an arrangement is disclosed in U.S. Pat. No. 3,562,366.
An improved repair technique has now been devised.
According to a first aspect, the invention provides a method of repairing a flaw or void in a body, the method comprising infilling the flaw or void with a repair material, wherein high frequency vibration means is applied to act on the body, the high frequency vibration means including a vibration delivery probe of a rigid material.
According to a second aspect, the invention provides apparatus for use in repairing a flaw or void in a body, the apparatus comprising high frequency vibration means including a vibration delivery probe of a rigid material, the probe being positionable to act on the body.
The use of a rigid material for the delivery probe (preferably a hard metallic material such as titanium) enables ultrasonic vibration of sufficient amplitude to be achieved to cause resultant desirable physical effects in the flowable (typically liquid) repair material.
The vibration means preferably comprises ultrasonic vibration means desirably operating substantially in the range 20 KHz-150 KHz (more preferably substantially in the range 35 KHz-55 KHz). The vibration means therefore preferably comprises ultrasonic vibration means arranged to effect vibration substantially in the range 20 KHz-150 KHz (more preferably substantially in the range 35 KHz-55 KHz). The ultrasonic vibration means preferably includes an ultrasonic transducer.
The vibration means is preferably applied in the region of the flaw or void. Desirably the probe is tracked along the direction of an elongate flaw or void (crack).
In one embodiment, the vibration means may be hand held and manipulated digitally by an operative.
The rigid vibration delivery probe preferably includes a contact surface or tip for contacting the body or other vibration transmission medium.
The rigid vibration delivery probe preferably comprises an elongate rigid probe extending from a high frequency generator to the contact surface or tip. The distal contact portion or tip of the rigid material probe is typically of smaller sectional area relative to a portion of the probe less distal. The cross sectional area of the contact surface or tip is preferably at or below 1 cm2 (more preferably at or below 0.5 cm2).
The technique is particularly useful where the flaw comprises a crack, break, pit or discontinuity in the material of the body connecting to a surface of the body, especially where the body comprises a sheet of material, particularly a glazing or window element.
The repair material preferably comprises a flowable repair material such as a fluid or the like, desirably a viscous fluid such as a resin. The repair material preferably has optical qualities (when hardened) substantially matching optical properties of the body. Desirably, the body is substantially transparent at least to one or more wavelengths of visible light.
In one embodiment, the repair material is first applied to at least partially penetrate the flaw or void, the vibration means being subsequently applied to effect enhanced penetration of the repair material into the flaw or void. Alternatively, the repair material and the vibration means may be applied contemporaneously.
In one embodiment, the repair material may be applied to the region of the flaw or void, a cover positioned over the repair material and the vibration means applied to act on the body. The vibration means may be applied directly to the cover, or, alternatively, the cover may be positioned to overlay an obverse surface of the body, the vibration means being applied to a reverse surface of the body. As a further alternative, the vibration means may be applied to a reverse surface or applied directly to the repair material in situ without utilisation of a cover. In a preferred embodiment, the vibration means is applied adjacent the flaw or void, advantageously at a level below the flaw or void. A coupling material (such as a coupling gel) may be applied to the body for enhanced vibration transmissive coupling of the vibration means.
According to a further aspect, the invention provides a kit for repairing a flaw or void in a body, the kit including:
i) apparatus as herein defined; and,
ii) repair material for infilling the flaw or void.
The apparatus may further include a cover sheet or strip for covering the resin in situ in the flaw or void and/or a vibration coupling material.
By providing high frequency vibration for the body to be repaired, the mechanical vibration of the body aids in effecting full penetration of the repair material into the flaw or void. Furthermore, where the repair material is a fluid or gel (such as a resin), the applied high frequency vibration acts to reduce the viscosity and promote flow of the repair material. De-gassing of such repair material is also promoted by the ultrasonic vibration which results in a superior optical quality repair.